When a wireless communication apparatus is not able to receive good reception from a cellular network, it is common to move antenna position or move the wireless communication apparatus to a location where good reception is available. However, in many situations, it is not feasible to move the wireless communication apparatus. Therefore, some wireless communication apparatuses are capable of coupling to external antennas and the external antennas may be then moved to positions with good reception.
Antenna cable could be expensive and subject to signal loss. In addition, different antenna cable may be needed for different frequency bands. This also increases operational cost and capital cost. A solution is needed to allow the wireless communication apparatus to have good reception with a cellular network without moving the wireless communication apparatus or without using a long piece of antenna cable.
FIG. 9A shows a prior art that a SIM card emulator sold by implementa gmbh is used for connecting a SIM socket of a cellular phone. According to the website of implementa gmbh, http://www.implementa.com/products/sim-emulators/, the SIM card emulator can: “use off-the-shelf Mobile Terminals with SIM cards stored in remote SIM Storages”, “fits most consumer phones and industrial modules” and “placed into the SIM Holder instead of a real SIM card Mobile Terminal is operated with Soft SIM while using any SIM card from a SIM Farm”. FIG. 9B shows another prior art that another SIM card emulator sold by implementa gmbh is used for connecting a SIM socket of a mobile modem. The cables used in both SIM card emulators shown in FIG. 10A and FIG. 10B are USB cables.